MICROWAVE ABSORPTION CHARACTERISTICS OF NANOCOMPOSITE SILICON CARBIDE-ALUMINUM OXIDE (SiC-A1203) POWDER

Abstract

In this dissertation work, SiC-Al203 composite powder was prepared by sol-gel method for the application to lightweight microwave absorbers, which were characterized by scanning electron microscopy (SEM), X-ray diffraction analysis (XRD) respectively. The results show that, the powder obtained consists of particles of which are composed of SiC and A1203 microcrystal with the grain size of approximately 80 nm. The variation of its microwave permittivity was investigated in the frequency range of 8-12 GHz using open circuit-short circuit method and absorption were calculated using absorption testing device (ATD) for different ratio of carbon in SiC-Al2O3 by varying thickness. The maximum reflection loss for the composite powder was obtained -22.67 dB with a thickness of 1.2 mm.